Chemical Reactor System and Methods to Create Plasma Hot Spots in a Pumped Media

ABSTRACT

Methods and apparatus are disclosed to produce gas vapor bubbles in a liquid media and collapsing the bubble to create a plasma hot spot. Generated bubbles are introduced and collapsing the bubbles results in the partial or total conversion of the internal and boundary layer gas and liquid phase content of the bubble to plasma, ionized gas and ionized liquid. Consequently, a change or increase in the reactivity of the elements and compounds in the gas or liquid phases of the bubble and the surrounding liquid media occurs.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of the priority of U.S. Provisional Application Ser. No. 61/385,392, filed Sep. 22, 2010, and U.S. Provisional Application Ser. No. 61/385,423, filed Sep. 22, 2010, the entire disclosures of which are expressly incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to pump systems and controllers to create an automated, customizable, chemical reactor.

BACKGROUND OF THE INVENTION

Cavitation caused by ultrasonic and hydrodynamic equipment and techniques has been used for catalysis of many known and well defined endothermic reaction traditionally implemented with high temperature/high pressure processes for many years. The advantage of cavitation as a mechanism of chemical catalysis is the effect of high pressure and temperatures achieved in the domain of effect near the collapsed bubble, the rate of heating being sufficient to start and sustain reactions in aqueous and other solutions. Reactions catalyzed by these means are numerous and include hydrolysis, hydrogenation, transesterification, hydrodesulfurization, polymerizations, protonation, and others. The field of ultrasonic sonochemistry is well established and the techniques of sonication as a catalyst for reduction and oxidation chemistry and numerous organic and inorganic degradation and synthesis processes based on aspects and principles of sonochemistry have been in use in academia for experimentation and production of exotic chemical species for many years.

Implementation of hydrodynamic cavitation and sonochemistry for commercial or industrial scale resource processing, chemical synthesis, waste recovery, recycling and remediation has arguably been curtailed by the nature of the mechanism used to catalyze reactions for these purposes—cavitation. While single bubble collapse as achieved in single bubble sonoluminescence has been demonstrated as a stable, controlled bubble collapse technique using the methods of ultrasonic cavitation, cavitation as applied in industrial processes almost invariably use multi-bubble cavitation as the catalytic mechanism. This technique, when used at high power levels on raw materials that are variable in composition, such as metal or mineral ores, mining influenced waster water, chemical process effluents, crude oil, waste biomass, surface or ground waters that have stratified and are compositionally variant based on location or depth or as a consequence of long detention, requires significant and continuous modification of process conditions to sustain economically feasible throughput rates. These types of changes to cavitation bases mechanism are difficult as both ultrasonic and hydrodynamic cavitation require limited and specific conditions to achieve the high temperature and pressure collapse characteristics required to sustain productive rates of specific reaction catalysis.

Ultrasonic sonochemical processes are dependent on specific frequencies, or specific ultrasonic wave generation surface or horn travel distances or both. Once these variables are optimized in process, changes to reagent composition, ambient pressures, temperature, dissolved gasses or other solvent or solute properties often immediately destabilize the bubble cloud formation and collapse, significantly halting or slowing reaction catalysis, rendering the continued application of the technique without process variable changes uneconomic. Adjustments to frequency and amplitude of the ultrasonic field directly affect the properties of the created and collapsing bubble, changing the resonant frequency. The changes to frequency or amplitude, ambient pressure, temperature or other solvent or solute properties may result in condition that, while producing cavitation, produce bubbles with properties of size, resonant frequency or collapse rate that are not optimal for the catalyzing the desired reactions or processing of the feedstock in its current condition. This limitation is due to the dependence of bubble properties on ultrasonic field frequency and amplitude. The bubble properties can be modulated through advanced process control of these process parameters, but only certain frequency and amplitude combinations are effective. As a consequence, reactive closed loop control of processes based on this mechanism is limited in the scope of variation, detrimentally affecting the economics of processes using this mechanism of reaction catalysis.

There are many hydrodynamic cavitation implementation techniques using a variety of methods to manipulate the formation and collapse of bubbles through pressure and flow control. In addition, custom fittings and shaped orifices and other fixture based techniques for laminar and other unusual flow patterns, with and without closed loop control, have been in used to produce cavitation and catalyze compositional degradations and synthesis. Hydrodynamic cavitational techniques also suffer from restrictions due to optimal condition requirements similar to ultrasonic cavitation, where variation in composition, viscosities, dissolved or suspended solids content, dissolved gasses and other properties of the solvent or solute detrimentally affect the properties and formation of the clouds of bubbles and their subsequent collapse rates, shapes and characteristics.

Both ultrasonic and hydrodynamic cavitation also result in cavitational damage to process circuit elements as conditions for controlled cavitation often result in insipient or other undesirable cavitational effects at or on surfaces or system components, resulting in component wear, significantly affecting process economics.

SUMMARY OF THE INVENTION

The present invention provides a solution to the aforementioned limitations of both hydrodynamic and ultrasonic cavitation. Rather than causing bubble collapse through cavitation, methods and configurations are provided to produce bubbles in a controlled way directly and then, also in a directly controlled way, collapse those bubbles at a specific rate to a specific size. In addition, the bubbles collapse while entrained in fluid flow, preventing undesirable bubble collapse upon process component surfaces. As the formation and collapse of the bubbles occurs independent of optimal flow, pressure, temperature, viscosity, and other solvent and solute properties, and the bubble sizes and collapse rates are directly controlled and not a function of effective ultrasonic amplitudes or frequencies, or fixed pressure or flow established in specialized fittings, this mechanism of bubble collapse can be applied to catalyze reactions economically across a broad range of feedstock variability.

Methods and apparatus are provided to produce gas vapor bubbles in a liquid media and collapsing the bubble to create a plasma hot spot. Generated bubbles are introduced and collapsing the bubbles results in the partial or total conversion of the internal and boundary layer gas and liquid phase content of the bubble to plasma, ionized gas and ionized liquid. Consequently, a change or increase in the reactivity of the elements and compounds in the gas or liquid phases of the bubble and the surrounding liquid media occurs.

In one aspect, methods and apparatus are provided that use the properties of a collapsing gas vapor bubble in a liquid media as a catalyst for reactions between elements or compounds contained in the gas or liquid phases of the bubble, or as a catalyst for reactions between elements or compounds contained in the bubble and the elements or compounds present in the bubble containing liquid media.

In another aspect, methods and apparatus are provided to form gas vapor bubbles in a liquid media and to collapse them in isolation from each other using a controlled hydrodynamically generated pressure pulse of sufficient magnitude, both in rate of pressure increase and ultimate maximum pressure that the bubble vibrates, for example at its eigenfrequency, during collapse for a sufficient interval of time to permit the formation of a plasma hot spot within the gas and liquid phases of the collapsing bubble.

In yet another aspect, a device is provided that permits concentrations of the gas and liquid phase constituents of the bubbles formed in a pumped media at a pump system inlet to be both directly and indirectly controlled, at the time of formation and during evolution through the various possible bubble sizes through to collapse as the bubbles pass from the pump inlet's low pressure zone through the pump at increasing pressure and out the discharge at a particular controlled maximum pressure.

In still another aspect, a pump system is provided based on a regenerative turbine pump with components arranged to allow controlled bubble production and introduction into the pump inlet and subsequent collapse of the bubbles entrained in the helical flow of the pump within the individual bucket chambers formed by the regenerative turbine pump impeller, wherein the bubbles are collapsed singly without the interfering effects of the collapse of adjacent bubbles.

In another aspect, methods and apparatus are provided for electric motor driven pump speed and pressure control. The pump control system dynamically calculates optimal pump speed and pump system pressures for one of the alternate apparatus configurations or applications, to start and sustain the formation in the pumped media of a specific number of gas vapor bubbles of a particular size and then subsequently collapse the same bubbles at a particular rate to a specific ultimate final bubble size.

The pump control system incorporates a controller that provides a speed setpoint signal to the pump motor drive and pressure setpoint signals used to operate pressure regulating valves controlling pump inlet, casing and discharge pressures.

The following description, with attached diagrams, provides details of the important aspects of the invention. Note, however, that the invention has other useful and novel aspects apart from those discussed. These additional aspects and advantages of the invention will become apparent when considering together the following detailed description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a piping and instrumentation diagram depicting an exemplary implementation of the apparatus of the present invention including a pump system, subsystems, components and apparatus controller used to create gas vapor bubbles in a pumped liquid media and collapse them to plasma hot spots, in accordance with several aspect of the invention;

FIG. 2 is a piping and instrumentation diagram illustrating an alternate configuration of the bubble generation apparatus subsystem depicted in FIG. 1, utilizing a venturi;

FIG. 3 is a piping and instrumentation diagram illustrating another alternate configuration of the bubble generation apparatus subsystem depicted in FIG. 1, utilizing an eductor;

FIG. 4 is a piping and instrumentation diagram illustrating yet another alternate configuration of the bubble generation apparatus subsystem depicted in FIG. 1, utilizing an inline gas injection;

FIGS. 5 a, 5 b and 5 c are cross-sectional views of the regenerative turbine pump shown in FIG. 1;

FIG. 6 is a flowchart showing examples of the controller's logic, including alternate operational sequences as required by the various functional configurations of the apparatus of the present invention, in accordance with several aspects of the invention;

FIG. 7 is a flowchart showing processing steps carried out by an application logic of the present invention;

FIG. 8 is a flowchart showing processing steps carried out by a bubble generation logic of the present invention; and

FIG. 9 is a flowchart showing processing steps carried out by a bubble collapse logic of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The apparatus of the present invention comprises several independent subsystems that can be configured as required by a particular application. The apparatus includes a regenerative turbine pump to effectively entrain and collapse bubbles. FIG. 1 depicts an exemplary piping and instrumentation layout of the apparatus and its subsystems. In the alternate configurations, the apparatus generates a controlled linear stream of particularly sized bubbles in a pumped liquid media at the inlet, but outside of the casing, of a regenerative turbine pump and then rapidly collapse the bubbles, while entrained in the helical pumped media flow within the blade turbine of the impeller of the regenerative turbine pump so that a plasma hot spot is formed at the center of each collapsed bubble.

Referring to FIG. 1, an exemplary apparatus is generally indicated at 10. FIG. 1 shows a basic system overview but depending on the bubble generation apparatus used, the basic system may be modified. Proceeding from the apparatus inlet downstream through to the apparatus discharge, the liquid flow into the apparatus begins with an inlet pipe 14 connected between a liquid source 12 and a liquid supply 20 through motorized liquid level control valve 16 using level control 18. The liquid supply 20 can supply a liquid that can be a single substance, mixture or solution and may be pressurized, heated or chilled. The liquid supply 20 delivery pressure at the pump inlet pipe 22 centerline is preferably equal to or greater than the net positive suction head required (NPSHr) by the regenerative turbine pump 60 at its expected maximum flow for the particular application, and is preferably greater than the expected maximum pressure required by the bubble generation apparatus 30. The liquid supply delivery pressure can be provided from a tank or other storage medium, allowing connection of the device in a batch process. Alternately, the liquid supply 20 could be an effluent from an upstream process, allowing installation of the apparatus in a production line. The formation of bubbles in the fluid stream and the processing of the fluid stream depends on the initial solution. If the initial solution contains carbon dioxide, a venturi can be used to form bubbles in the fluid. If the initial solution does not contain carbon dioxide, carbon dioxide bubbles can be added to the solution for subsequent processing. Processing of the solution is undertaken through a closed-loop feedback where process variables are adjusted as solution is processed to optimize processing as will be described.

When the regenerative turbine pump 60 is operating, the pumped liquid media will flow from the liquid supply 20, through the pump inlet pipe 22, then through an inlet pressure control valve 24 with a motorized inlet valve pilot regulator 26. The controller 100 actuates the motorized inlet valve pilot regulator 26 as directed by controller logic 101 and application logic 106 in response to conditions in the pumped media at the pump inlet pipe 22, such as pressure and temperature measured by inlet pressure and temperature sensors 111 and 112, respectively. Pump inlet pressure sensor 111 may include pump pressure element 111 a, pump pressure transmitter 111 b and pump pressure indicator 111 c. Temperature sensor 112 may include temperature element 112 a, temperature transmitter 112 b and temperature indicator 112 c. The sensors comprise a detector element to measure and a transmitter to send the value. While the sensors are shown as discrete devices, the sensors could be a single device. Values sent from transmitters are shown to users on indicators, which can be local or remote gauges or computer graphical monitors. An example of a suitable commercially available pressure sensor/transmitter is Ashcroft Xmitr, 0-100 psi, 3″. The primary control algorithms, operation and detection sequencing instructions and setpoints or setpoint algorithms, are stored in the controller, which can be a PC, Panel-PC, PLC (programmable logic controller) or some other specific purpose programmable HMI (human-machine interface) device or controller. An example of a suitable commercially available PLC is Allen-Bradley Micrologix 1400 Model 1766-L32BWAA. An example of a suitable commercially available PLC software with PID algorithms is RSLogix 500 Professional. An example of a suitable commercially available PC is HP Compaq dx2450.

The controller 100 calculates and adjusts the pumped liquid media pressure setpoint downstream of the inlet pressure control valve 24 by adjusting the inlet pressure control valve 24 using the motorized inlet valve pilot regulator 26. These adjustments could be made using the inlet pipe 22 pumped media condition information gathered by the pump inlet pipe 22 sensors 40, 111, 112, regulating pressure as required by the inlet bubble generation apparatus 30 and enabling sustained generation of bubbles of the required size and number for a particular application. Inlet bubble detection apparatus 40 may include sensor element 40 a, transmitter 40 b and indicator 40 c.

Depending on the specific application and the nature of the pumped media, proper pressure control of the pumped media flowing through the pump inlet pipe 22 may include detection of other parameters of the pumped media's composition or condition, either apart from or in addition to temperature and pressure, such as flow rate, viscosity, two-phase void fraction, salinity, pH, total VOC (Volatile Organic Compound), BOD (Biological Oxygen Demand), or some other property or metric. When detection of conditions other than current pressure and temperature are used by the controller 100 to regulate apparatus inlet pressure, the controller logic 101 and application logic 106 may contain steps that detect and identify the additional sensors and evaluate the values therefrom in conjunction with the measured inlet pressure and temperature, calculating a new position setpoint for the motorized inlet valve pilot regulator 26, which in turn adjusts the position of the inlet pressure control valve 24, regulating the pressure in the pump inlet pipe 22 at the bubble generation apparatus 30. In this way, changes in liquid supply temperature, pressure or other parameter values that occur during the operation of the apparatus, such as a level drop in a liquid supply 20 tank, turbulence in pump inlet pipe 22, performance change in an upstream connected process, change in pressure of liquid supply 20, or a change in the flow rate requirements of the downstream subsystems can be detected and compensated for using closed-loop control, maintaining pressure and flow as required by the bubble generation apparatus 30.

Next, continuing with FIG. 1, the pumped media flows from the inlet pressure control valve 24 through the inlet bubble generation apparatus 30. Bubbles are formed using one or more of at least three alternate possible configurations, although there are other possible effective methods of bubble production that could be adapted for use in the apparatus. It is expected that a useful configuration of the inlet bubble generation apparatus 30 will produce a steady, linear bubble stream in the range of approximately 100 to approximately 9,000 bubbles per second, as required by a particular application, with stable bubble diameters in the range of approximately 0.5 microns to approximately 1 mm, again as required by a particular application. Particular applications could have different ranges of amounts and sizes of bubbles. Also, it is desirable for the bubble generation apparatus 30 to produce a linear stream of bubbles as opposed to uncontrolled clouds of bubbles produced by some types of bubblers and elements of cavitation reactors, even if the number and size of bubbles in the cloud are controlled. The following three configurations of the bubble generation apparatus 30, while not representative of all possible alternatives as might be required by a particular application of the apparatus, provides for bubble production in sufficient number, size, and placement, and demonstrate some desirable features of potentially useful alternate bubble generation configurations. There are differences in performance features of the alternate configurations.

Referring now to FIG. 2, an alternate configuration of bubble generation apparatus 30 involves a modified apparatus generally indicated at 210. This configuration uses a large bore venturi 270 installed inline before the inlet bubble detection apparatus 40, if the system includes a bubble detection apparatus 40, or in-line before the regenerative turbine pump 60. In this configuration, the apparatus receives a liquid supply 20 that is sparged at a controlled rate by a compressor 250 with a feedstock gas supply or gas mix 252, as regulated by the gas supply pressure controller 211, which controls motorized gas pressure control valve 212. Consequently the gas supply 252 is dissolved in the liquid supply 20 and the gas-saturated liquid is delivered to the inlet pipe 22 at or above standard pressure. Note that the addition of a gas to the liquid supply 20 may not be required for applications where the liquid supply contains volatile elements or compounds. In these cases the vapor pressure of the liquid might be sufficient for bubbles to form as they pass through the venturi 270 without the addition of an external gas to the liquid supply 20 solution. The liquid supply pressure is detected, transmitted and indicated by the liquid supply sparging gas sensor 254 which may include sensor element 254 a, transmitter 254 b and indicator 254 c. The liquid supply 20 pressure is read by the liquid supply sparging gas compressor speed control programmable logic controller (PLC) 256 and compared to the compressor speed setpoint 258 or the sparged liquid supply pressure setpoint. PLC 256 then retrieves the current compressor speed, recalculates a new compressor speed setpoint 258, and transmits this together with the liquid supply 20 pressure as the process variable to the liquid supply sparging gas compressor speed control proportional-integral-derivative controller (PID) 257. PID 257 sends a ranged analog or digital signal to the compressor speed controller 259 that causes the controller to vary the power frequency delivered to the motor (not shown) of a compressor 250 so that it rotates at the compressor speed setpoint 258.

As a result of this sparging action, the gas or gas mix supplied is dissolved into the liquid supply as a function of the solubility of the supplied gas 252 in the supplied liquid 20 at the pressure maintained in the liquid supply 20. The saturated liquid is drawn across the venturi 270 by action of the regenerative turbine pump 60 resulting in a pressure drop in the venturi throat 272, as controlled by the speed of regenerative turbine pump 60, pump inlet pipe 22 or discharge pipe 75 pressure regulation, liquid supply pressure or some combination of thereof. As the gas-saturated pumped liquid media passes through the venturi throat 272, some of the dissolved gas or gasses and some of the pumped liquid media vaporize. Consequently, bubbles are formed with elements or compounds contained in both the gas supply 252 and the liquid supply 20. The specific gas vapor fractions in a bubble are calculated for a particular application using Bernoulli's equation, considering the dynamic dissolved gas and liquid vapor pressures, the differential pressure caused by the pressure drop across the venturi throat 272, the velocity of the pumped media, the static operating pressure at the inlet of the bubble generation apparatus 30, and any other property of the pumped media that can affect the gas vapor composition of the bubbles. This method enables automatic mixing of the dissolved gas and pumped media liquid gas vapor compounds in the bubbles. An example of a venturi for use in the present apparatus is the Venturi Tee made by LASCO Fittings, Inc., Brownsville, Tenn.

Referring now to FIG. 3, a second alternate configuration of the bubble generation apparatus 30 includes a modified apparatus generally indicated at 310. This configuration uses an eductor 370 installed inline in the pump inlet pipe 22 and outfitted an orifice 372 sized to govern the size and number of the generated bubbles. A gas supply 352 is maintained by a self-contained gas supply pressure controller 353, and motorized gas pressure control valve 351, at or above the maximum delivery pressure required by the eductor 370 for a particular application. Pressure at the eductor orifice 372 is controlled by a motorized gas pressure control valve 374 installed between the gas supply 352 and the eductor 370, regulating gas delivery pressure. The eductor gas supply pressure sensor 375, which may include sensor element 375 a, transmitter 375 b and indicator 375 c, sends a ranged analog or digital signal representing the current regulated eductor gas delivery pressure to the eductor gas supply pressure control PLC 376. PLC 376 reads this current pressure signal and transmits it as the process variable together with the eductor gas supply pressure setpoint 377 to the eductor gas supply pressure control PID 378. PID 378 continuously recalculates and transmits a new analog or digital position signal to motorized gas pressure control valve 374 indicated by the motorized gas pressure control valve position indicator 379, maintaining the eductor gas supply pressure setpoint 377. Bubbles are created with a vapor content controlled directly by adjusting the internal diameter of orifice 372, the pumped media liquid pressure and the eductor gas supply pressure setpoint 377. This method is suited for applications where pump inlet pipe 22 or gas supply 352 pressures are low and enables indirect regulation of the gas and pumped liquid media vapor composition of the bubbles.

Continuing now with FIG. 4, another alternate configuration of the bubble generation apparatus 30 includes a modified apparatus generally indicated at 410. This configuration uses a gas injection nozzle 470, which is sized and shaped to produce bubbles based on flow rate and throughput of the system. The nozzle 470 is installed in the pump inlet pipe 22 line, pointed downstream and axially centered in the pump inlet pipe 22 before the inlet bubble detection apparatus 40 or the regenerative turbine pump 60, optionally followed by a vortex fitting 472 such as, for example, a standard NIBCO vortex insertion feeder manufactured by NIBCO, Inc., from Elkhart, Ind., or a Steinen Tan-Jet nozzle, manufactured by Wm. Steinen Mfg. Co., based in Parsippany, N.J., to assist bubble entrainment. In this arrangement, a gas supply 452 is connected to a compressor 450 which discharges the gas into a pressure regulated line. Inline gas injection nozzle pressure and compressor speed control PLC 476 reads the ranged analog or digital injector pressure signal from the inline gas injection nozzle pressure sensor 475 which may include element 475 a, transmitter 475 b and indicator 475 c. PLC 476 continuously retrieves the current inline gas injection nozzle pressure setpoint 477 and recalculates a new pressure setpoint, transmitting a ranged analog or digital signal to the motorized gas pressure control valve 474 that regulates the injection nozzle pressure. If the inline gas injection nozzle pressure setpoint 477 cannot be achieved by the gas supply 452 pressure, as regulated by the gas supply pressure controller 453, and motorized gas pressure control valve 412, then PLC 476 starts the compressor 450, and using the gas injection nozzle pressure 475 as the process variable, upwardly adjusts the inline gas injection nozzle compressor speed setpoint 458 until the inline gas injection nozzle pressure setpoint 477 is fractionally exceeded. Fine downward gas pressure adjustment can be accomplished by changing the pressure setpoint transmitted to the motorized gas pressure control valve 474. Once PLC 476 calculates a pressure setpoint, it is transmitted to inline gas injection nozzle pressure control PID 478, with injection nozzle pressure 475 as the process variable. PLC 476 relays the current compressor 450 motor (not shown) speed from the compressor speed controller 459 to inline gas injection nozzle compressor speed control PID 457 along with the current compressor speed setpoint 458. This method enables bubble generation across a wide range of operating pressures, and direct control of bubble content, size and number by varying the inline gas injection nozzle pressure setpoint 477 or the inline gas injection nozzle 470 shape or size, in addition to the pump inlet pipe 422 pressure as regulated by the inlet pressure control valve 424.

Referring back to FIG. 1, the pumped liquid media containing entrained bubbles passes through the optional inlet bubble detection apparatus 40. In fixed or low flow applications, or with feedstock that is invariant in composition, it may be sufficient to monitor the bubble generation apparatus 30 operating conditions as reported by inlet pressure 111 and temperature 112 sensors, using a specific inlet bubble generation apparatus 30 configuration. Where such correlations are inadequate, or where bubble production parameter values must be more precisely controlled, additional analog or digital detection of the size and number of bubbles actually created may be required. In these applications, the controller 100 uses controller logic 101 that receives the analog or digital bubble production data signal output from the inlet bubble detection apparatus 40 and, in conjunction with other data from detection inlet sensors 111 and 112, calculates new operational parameter values, such as the pressure of the inlet bubble generating apparatus 30 as set by the inlet pressure control valve 24, or the gas eductor (FIG. 3, 370) or injector (FIG. 4, 470) line pressure, as used in the alternate bubble generation apparatus 30 configurations, establishing closed-loop bubble production control. The controller logic 101 could be programmed using any suitable high or low-level computer programming language, and could be embodied as computer-executable instructions stored in a computer-readable medium, such as flash memory or other type of non-volatile memory. The inlet bubble detection apparatus 40 can be any one of a number of devices that are designed to produce a ranged analog or digital signal that corresponds to the number and sizes of bubbles present in a particular location in a two phase liquid media, such as an interferometric laser imaging sizer, a broadband sound velocimeter, Doppler Sonography or another acoustic technique for bubble sizing. Properties of the pumped media such as composition, opacity, inclusions, temperature, as well as the size and number of bubbles to be produced and the intended function of the invention will guide the selection of the appropriate inlet bubble detection apparatus 40 to be used in conjunction with a particular application.

Continuing with FIG. 1, the pumped liquid media containing the produced bubbles passes from the inlet bubble detection apparatus 40 and enters the regenerative turbine pump 60. Next, the process water containing the entrained bubbles passes from the inlet bubble detection apparatus 40 and enters the regenerative turbine pump 60. The turbine pump design with pump inlet, discharge, casing, channel layout, and connecting piping arrangements and low internal clearances enables the regenerative turbine pump to entrain gas bubbles in a helical flow of the pumped water within the pump casing's channel, preventing the bubbles from adhering to or forming on the internal surfaces of the pump or where the pumped bubble containing liquid media flows.

Referring now to FIG. 5, the bubbles and pumped liquid media pass through the pump inlet 61, which preferably has a smooth, straight-walled bore with minimal change in internal diameter across the pumped media flow path and which preferably intersects the casing tangentially, so that turbulence within the pump inlet, and consequently disruption to bubble size and location in the flow path, is minimized. The pumped media then passes into the casing 62 of the regenerative turbine pump 60 where the pumped liquid media is forced, by containment within the buckets 64 formed by impeller blade 65 within the pump casing's annular space, to flow in a helical pathway 66. This occurs as the pumped liquid moves with the pump impeller 63 through the pump casing 62. The pumped liquid media rotates about the axis of the direction of flow, causing an entrained bubble 67 to remain at the center of the flow path, preventing its adhesion to the pump casing's 62 internal surfaces and restraining it to a single impeller bucket 64.

The rotational speed setpoint of the pump impeller 63, determined during application design, and then subsequently maintained or adjusted as required by the controller 100 (see FIG. 1) during apparatus operation, is set so that the number of impeller buckets 64 that pass by the pump inlet 61 per second closely matches the number of flow entrained bubbles that pass through the pump inlet 61 per second. In addition, the pump speed setpoint and the regulated pump inlet and discharge pressure setpoints are those values that cause the pumped media flow rate to be such that the bubbles are moved singularly into the impeller buckets 64, minimizing or eliminating the incidence of impeller buckets 64 that contain multiple bubbles or none during operation. Finally, the pump impeller 63 rotational speed and pump discharge 68 pressure are so adjusted and maintained during operation that the bubbles individually entrained in the pumped liquid media flow, and contained within individual impeller buckets 64, are collapsed as the surrounding pumped liquid flows from the pump inlet 61 to the pump discharge 68 at cut-water 69 and the pressure within the bubble containing impeller buckets 64 increases from the pump inlet 61 pressure to the final regulated pump discharge 68 pressure. In this way the initial and final bubble sizes, rate of bubble collapse, and final collapsed bubble core temperature and pressure, and consequently the resulting changes in the pumped liquid media and bubble content properties, composition or reactivity, are directly and mechanically controlled. The actual rate of bubble collapse is determined by the difference between the initial and final bubble size and the rate of pressure rise within the pump casing 62. Direct, automatic, mechanical control of these parameter values allows the apparatus function to be modulated, both initially and dynamically during operation for optimal performance of a particular application.

An example of a regenerative turbine pump for use in the present apparatus is the Regenerative Turbine Chemical Pump made by Roth Pump Company, Rock Island, Ill. Roth regenerative turbine chemical duty pumps provide continuous, high pressure pumping of non-lubricating and corrosive liquids. These regenerative turbine pumps are provided with one piece, machined self-centering impellers for operation with a wide variety of chemicals with process heads up to 1400 ft. (427 m.), 600 psi (40 bar), TDH at 3500 rpm, NPSH from 3 to 14 ft. (0.91 to 4.2 m.), and temperatures to 450° F. (232° C.). Another example of a regenerative turbine pump for use with the present apparatus is Dynaflow Regeneration Turbine Pump made by Dynaflow Engineering, Middlesex, N.J. Another example of a regenerative turbine pump for use with the present apparatus is Model MT5003P3T6 made by Warrender, LTD., Wood Dale, Ill.

Continuing downstream of the pump casing and referring to FIG. 1 the pumped liquid media containing partially or totally collapsed bubbles passes out of the pump casing and through the pump discharge 68. The pump discharge 68 preferably has a smooth, straight-walled bore with minimal change in internal diameter across the pumped media flow path and also preferably intersects the casing tangentially, so that turbulence is minimized.

Continuing with FIG. 1, the pumped liquid media passed through the optional discharge bubble detection apparatus 70 which may include sensor element 70 a, transmitter 70 b and indicator 70 c. As with inlet detection, the controller 100 can monitor conditions or properties of the pumped media in order to determine the correct speed setpoint 109 of the regenerative turbine pump 60 and the correct pressure setpoints 108 of discharge pressure control valve 80. In applications where total collapse of produced bubbles is required, detection and measurement of the number and size of bubbles that remain in the pumped liquid media stream discharged from the regenerative turbine pump 60 can be used to recalculate a correction to the pump speed 109 or the discharge pressure 108 setpoints. In most applications it is expected that the rate of bubble collapse within the regenerative turbine pump 60 will increase as the maximum pump discharge pressure 108 setpoint, as controlled by the regenerative turbine pump 60 impeller (FIG. 5C) speed and regulated by the discharge pressure control valve 80, is increased.

Once bubble generation is underway, the optional discharge bubble detection apparatus 70 is used to detect and measure any bubbles that remain in the pumped media flow downstream of the regenerative turbine pump 60. If bubbles are detected in the discharge flow, where none should be present, or if bubbles larger than those that should be present are detected, then the discharge pressure setpoint can be increased.

An increase in regenerative turbine pump 60 discharge pressure can be accomplished in at least two ways. First, where the current discharge pressure setpoint, as regulated by the discharge pressure control valve 80, is less than the shutoff, or maximum, pressure of the regenerative turbine pump 60 while operating at its current speed setpoint, then the discharge pressure control valve 80 is used to increase the discharge pressure setpoint. Second, where the current discharge pressure setpoint is equal to the maximum possible at the current regenerative turbine pump 60 speed setpoint, then the impeller 63 speed setpoint is increased. Consequently, the maximum possible discharge pressure setpoint is increased. Once the regenerative turbine pump 60 impeller 63 speed setpoint is increased, additional upward discharge pressure increase and regulation is accomplished by increasing the discharge pressure setpoint of the discharge pressure control valve 80. In this way, the discharge pressure setpoint and the regenerative turbine pump 60 speed setpoint can be manipulated independently, allowing a particular application to achieve and sustain a particular discharge pressure setpoint, as required to collapse the generated bubbles, while at the same time varying the regenerative turbine pump impeller 63 speed setpoint. This enables the precise timing of the impeller buckets 64 (FIG. 5A) passing by the regenerative turbine pump 60 inlet to the number of bubbles output by the bubble generation apparatus 30, enabling the aforementioned desired collapse of bubbles singularly in an isolated way at, for example, their eigenfrequencies.

Again, continuing with FIG. 1, the pumped liquid media now passes by the discharge pressure 113 and temperature sensors 114, as well as any other detectors or sensors that are installed to measure the composition or condition of the pumped liquid media in the discharge pipe 75. The discharge pressure and temperature sensors 113, 114 may include sensor elements 113 a, 114 a, transmitters 113 b, 114 b and indicators 113 c, 114 c. Finally, the pumped liquid media flows through the discharge pressure control valve 80 and out of the apparatus. The discharge pressure control valve 80 is configured for regulation of pumped liquid media pressure upstream of the discharge pressure control valve 80, that is, pressure regulation occurs in the discharge pipe 75 between the regenerative turbine pump 60 and the discharge pressure control valve 80. The inlet pressure control valve 24 regulates pump inlet pipe 22 pressure downstream of the inlet pressure control valve 24. In this way, the pressure to collapse the generated bubbles required by a particular application is set and regulated by combined manipulation of the discharge pressure control valve 80 pressure setpoint 108 and the regenerative turbine pump 60 speed setpoint 109. A receiving vessel or downstream process connection is provided after the discharge pressure control valve 80.

The pumped liquid media and gas handling subsystems of the apparatus may be outfitted with relief, bypass or other unloader valves (not shown) and other safety devices and features as required by the nature of the particular application. Additionally, inlet and discharge isolation (not shown) and check valves (not shown) should be installed where required to prevent improper flow and to provide for apparatus isolation, testing and service.

Referring still to FIG. 1, the controller 100 provides both operation condition detection and control services for the apparatus. In its role as a pump motor control system, the controller 100 generates and transmits to the variable frequency drive 126 motor controller start, stop and other variable frequency drive function commands and the pump motor speed setpoint 109 signal. The variable frequency drive 126 is connected to and provides power for the regenerative turbine pump 60 motor, controlling the motor's rotational speed and consequently the coupled regenerative turbine pump 60 speed as directed by the motor speed control pilot signal received from the controller 100. In addition to regenerative turbine pump 60 motor control, the controller 100 operates the motorized inlet valve pilot regulator 26 and motorized discharge valve pilot regulator 82, varying the inlet pressure, as regulated by the inlet pressure control valve 24, and the discharge pressure, as regulated by the discharge pressure control valve 80. The controller 100 also monitors and can record apparatus subsystem parameter values received from the pump inlet pipe 22 and discharge pipe 75 sensors 40, 70, 111, 112, 113, 114 and recalculates setpoints related to the system's operation as required by a particular application.

The controller logic 101 stored and executed by the controller logic PLC 140 provides the controller 100 and the apparatus operational sequence and other functions. The controller logic 101 can be changed as required to include functions specific to a particular apparatus configuration. FIG. 1 shows an exemplary set of detectors and controlling devices for implementing the operational methods explained herein. Other configurations of the apparatus are possible using other equipment, detectors and controllers not shown, or not using some of the shown apparatus subsystems or components. To accommodate possible physical configuration changes to the apparatus, the controller logic 101—those programming instruction pertaining to the installed apparatus and controller 100 device identification, state detection, control and task distribution—can be altered such as by uploading the program to an external computer or device for storage, required modification and subsequent download back to controller logic PLC 140. Alternately, separate instances of apparatus configuration specific controller logic 101 can be stored locally in the controller 100 or in an external computer or device, to be uploaded or executed as required by the controller logic PLC 140. Additionally, it may be necessary to change the operational sequence of the apparatus for a particular application. Application logic 106—such as the order of sensor or detector evaluation, the order of setpoint modification, the algorithms for setpoint modification, or algorithms used to identify and recover from operational fault states—may be stored in or accessible to and executed on the controller logic PLC 140. As with controller logic 101, an unique version of application logic 106 can be stored locally in the controller or on an external device or application logic 106 can be uploaded to an external device or computer, modified, and downloaded back to the controller logic PLC 140. Inlet pressure setpoint 107 and discharge pressure setpoint 108 data that describe operational parameters such as pressure, temperature and bubble properties, and pump motor speed setpoint 109 data, are provided as individual values, independent or dependant values or value ranges or algorithms used to calculate values or value ranges, may be stored with or accessible to controller logic PLC 140 and can be uploaded and downloaded to an external device or computer. In each case, where data or program code stored in or accessible to the controller logic PLC 140 is to be modified, rather than uploading, modifying and downloading existing setpoint data 107, 108, 109, controller logic 101 or application logic 106 program code, it is also possible to access and modify this information on or accessible to the controller 100 directly using an external device or computer. In addition, an operator control panel (not shown) can be provided to allow manual control of the apparatus, manual entry of setpoint data 107, 108, 109, manual manipulation of or interaction with controller logic 101 or application logic 106, or manual control of invention subsystems or components directly, such as the pressure control valves 24, 80 or the variable frequency drive 126.

The external link PLC 118 provides a direct connection and controller 100 interface to an external device or computer, direct access to the data and program code stored on or with the controller PLC 140 from an external device, and logic for automated or externally directed upload and download of reduction logic 106 and controller logic 101 and setpoint data 107, 108, 109. Where the apparatus is part of a larger system, the controller logic 101 can incorporate steps to accept directives from and report operational parameter values and status to an external system, computer or device. In these cases, the external link PLC 118 can be configured and programmed to marshal this external communication and control between the external device or computer and the controller logic PLC 140.

Note that FIG. 1 depicts discrete PLCs in the controller 100, such as one for external link 118 and one for controller logic 140, as well as others such as inlet pressure control PLC 130, discharge pressure control PLC 102 and pump motor speed control PLC 104. These functions could be combined in a single PLC, a personal computer (PC) such as PC 119 or other similar device. In addition, while the external link PLC 118 and controller logic PLC 140, as well as the other PLC's 130, 102, 104 and PID's including inlet pressure control PID 135, discharge pressure control PID 103 and pump motor speed control PID 105, are shown in FIG. 1 to be incorporated into a single controller, devices performing these functions could be installed in separate locations as part of separate controllers—this alternate control component arrangement may be likely where the apparatus is incorporated into a larger overall process or system. Also, while controller logic 101 and application logic 106 are depicted in FIG. 1 as residing in and executing on the controller logic PLC 140, it is possible that the controller logic 101 could reside in and execute on a different PLC, PC or other similar device than the one that stores and runs application logic 106, and these separate PLC or alternate devices could also reside in separate controllers. Similar variation in component function distribution, grouping or placement is possible with the other sensor-transmitter-indicator devices such as 40, 70, 110, 111, 112, 113, 114, 135, PLC 130, 102, 104 and PID 135, 103, 105 as well. The controller 100 component arrangements and functions rendered in FIG. 1 are exemplary of stand-alone, self-contained operation and control of the apparatus, for use as depicted when the system is configured and connected upstream and downstream as shown, or as a design feature guide for different physical configurations of the invention or where the invention is incorporated as a single element or step in a multi-function or multi-step process. Consequently, in the discussion of the controller 100 component functions contained herein, it should be understood that where a particular PLC, PID or other device with specific functions is discussed, a PC, PLC or other functionally equivalent device could be substituted for the one described. Additionally, discrete functions performed by the described controller 100 component may be performed by another device along with other unrelated functions.

Individual subsystem controls and instrumentation may be grouped in the controller 100 by related function and may be monitored and controlled as a group by a discrete individual PLC, PC or other similar device. This permits discrete subsystem data storage and programming. In this way the addition, configuration change or removal of subsystems or subsystem components requires only the addition, change, reprogramming or deletion of those corresponding elements of the controller 100 directly responsible for the state detection or control of the affected subsystem or component.

Controller logic PLC 140 executes the controller logic 101 and application logic 106 program instructions that direct the operational sequence of the apparatus subsystems, as previously described, and responds to external computer or operator requests. PLC 140 also handles operational sequence interruptions and operational parameter value data requests generated by the subsystem controllers PLC 130, PLC 102 and PLC 104. PLC 140 may also be used for handling and maintaining overall operational status information and requests for this information transmitted from the subsystem controllers and for relaying setpoint and subsystem status information between the apparatus subsystems as they request such data or status for their operation. Operational limit conditions, error states and other events then occur during operation that require the apparatus to change operational mode, halt, reset or communicate an operational or component status or alarm to an operator, external computer or device may also be handled by the controller logic PLC 140.

The inlet pressure control PLC 130 receives from controller logic PLC 140, initially and periodically as required, inlet pressure setpoint 107 data, as values, value ranges or as an algorithm used to calculate a setpoint value or value range using pump inlet pipe 22 sensor 40, 111, 112 data. The inlet pressure setpoint 107 data values specify, for a particular application, the required pressure and/or temperature of the pumped media and/or the required amount and/or size of bubbles that emit from the bubble generation apparatus 30, or both. Additionally, inlet pressure setpoint 107 data may be provided for other properties of the pumped media at the pump inlet pipe 22 or of the generated bubbles. Inlet pressure control PLC 130 receives ranged analog or digital signal input from sensor transmitters whose elements are mounted at the bubble generation apparatus 30 inlet, such as the inlet pressure transmitter 111 b and the inlet temperature transmitter 112 b. Inlet pressure control PLC 130 is also connected to and receives a ranged analog or digital signal input from the inlet bubble detection apparatus 40, which may be interpolated to represent the size and number of bubbles detected. Utilizing inlet pressure control application logic 106 and inlet pressure setpoint 107 data, inlet pressure control PLC 130 monitors pump inlet pipe 22 temperature, pressure, and other properties, as well as bubble number and size, and recalculates continuously during operation the required target inlet pressure setpoint 107. During operation, the inlet pressure setpoint 107 required to maintain uniform, stable, continuous operation of the bubble generation apparatus 30, as specified by a particular application, may vary due to pump inlet pipe 22 or discharge pipe 75 turbulence, pumped media flow rate or temperature change, pump speed change, discharge pressure change, or change in another property of the bubbles or pumped media. As these changes occur, the properties of the generated bubbles may vary outside an application's specified range. Inlet pressure control PLC 130 can calculate a new inlet pressure setpoint 107 expected to mitigate the bubble property changes and restore bubble production to the application's specifications. This processing continues until interrupted by controller logic PLC 140, which can provide new inlet pressure setpoint 107 data or direct inlet pressure control PLC 130 to set a specific inlet pressure setpoint 107 and stop processing. In addition, the controller 100 can provide panel mounted operators (not shown) and pump inlet pipe 22 sensor indicators—inlet pressure indicator PI 111 c, inlet temperature indicator TI 112 c—that enable manual control of the inlet pressure setpoint 107. An inlet pressure setpoint 107 input via a panel operator may be processed by controller logic PLC 140 as setpoint data from an external device or computer would be and as a specific inlet pressure setpoint 107 with no additional processing by inlet pressure control PLC 130.

Once an inlet pressure setpoint 107 is calculated by inlet pressure control PLC 130 it is transmitted together with the current inlet pressure process variable to inlet pressure control PID 135. PID 135 continuously receives updated inlet pressure process variable and setpoint pressure values. PID 135 then calculates and transmits a ranged analog or digital signal corresponding to the position of the motorized inlet valve pilot regulator 26 required to set the inlet pressure control valve 24 to the inlet pressure setpoint 107. If the motorized inlet valve pilot regulator 26 is equipped with its own controller, inlet pressure control PID 135 will transmit a ranged analog or digital signal representing the inlet pressure setpoint 107 to the motorized inlet pilot valve's controller, which will in turn calculate the required pilot valve position to set the inlet pressure control valve 24 to the inlet pressure setpoint 107.

Alternately, controller logic PLC 140 can direct—either as part of its intrinsic logic or as commanded by an external computer or device or operator—inlet pressure control PLC 130 to use the analog or digital signal from the inlet bubble detection apparatus 40 as the inlet pressure control PID 135 process variable. Two sequential operational modes are employed to implement this control technique. First, inlet pressure control PLC 130, using the aforementioned inlet pressure setpoint 107 handling techniques and in conjunction with inlet pressure control PID 135, sets the inlet pressure so that the bubble generation apparatus 30 is operating within application specifications for bubble number and size. Second, the interpolated analog or digital signal from the inlet bubble detection apparatus 40 corresponding to the optimal bubble properties is captured and used as the controlling setpoint in place of the inlet pressure setpoint 107. This captured setpoint signal is continuously transmitted together with the signal from the inlet bubble detection apparatus 40, which in this case is used as the process variable, to inlet pressure control PID 135. PID 135 subsequently varies the position signal or pressure value transmitted to the motorized inlet valve pilot regulator 26, and consequently the regulated pressure at the bubble generation apparatus 30 inlet, in response to changes in bubble properties. In this way, closed loop control of the inlet pressure required by the bubble generation apparatus 30 is continued in response to the inlet bubble detection apparatus 40 signal. Inlet pressure control PLC 130 can continue its control operation in this alternate mode or switch back to inlet pressure setpoint 107, and detected inlet pressure process variable based control of inlet pressure control PID 135.

Once the motorized inlet valve pilot regulator 26 position is set, the inlet pressure control valve 24 can maintain the set pressure without further pilot control adjustment. Consequently, in applications where repeated or continuous change in or adjustment of the inlet pressure setpoint 107 does not occur during normal operation, the inlet pressure control PID 135 can be omitted or replaced with a proportional-integral controller (PI) or other similar, simpler, proportional controller. It is understood, however, that in many applications, fine control of inlet pressure setpoint 107 variations will be required to sustain optimal apparatus operational parameter values.

Once bubbles are generated, they pass through the regenerative turbine pump 60 and are collapsed. Discharge pressure control PLC 102 and pump motor speed control PLC 104 both contribute to the process of pump discharge 68 and discharge pipe 75 pressure control. Discharge pressure control PLC 102 receives discharge pressure setpoint 108 data from controller logic PLC 140, initially and periodically, similar to inlet pressure control PLC 130, as values, ranges or algorithms to calculate the discharge pressure setpoint. Discharge pressure control PLC 102 receives and monitors ranged analog or digital signals from the discharge pipe 75 mounted sensors: discharge pressure sensor 113; discharge temperature sensor 114, and discharge bubble detection apparatus 70, as well as any other properties of the discharged process water that the apparatus might be additionally equipped to detect. Discharge pressure control PLC 102 continuously monitors the various aforementioned discharge pipe 75 process variables and recalculates the discharge pressure setpoint 108 required to collapse the bubbles at the rate and to the size required by the particular application. Similarly to bubble generation control, bubble collapse rate, final bubble size, or total bubble collapse control may require variable discharge pressure and pump rotation speed setpoints as operational parameters change. Discharge pressure control PLC 102 monitors discharge pipe process variables and continuously recalculates the discharge pressure setpoint 108 expected to mitigate any variance from bubble collapse specifications for an application.

Operation of the discharge pressure control valve 80, through operation of the motorized discharge valve pilot regulator 82 by discharge pressure control PID 103, as directed by pressure control PLC 102, utilize signal types, signal processing, process variable selection—such as discharge pressure or discharge bubble detection apparatus 70 signal—and operational considerations and control techniques similar to the analogous pump inlet pipe 22 pressure control accomplished by inlet pressure control PLC 130 and PID 135, motorized inlet valve pilot regulator 26 and inlet pressure control valve 24. Remote control of the discharge pressure setpoint 108 by an external computer or device can be relayed through controller logic PLC 140 and discharge pressure control PLC 102. Also, as is the case with manual pump inlet pipe 22 pressure control, manual discharge pipe 75 pressure control is possible using panel mounted operators (not shown) and the feedback from the panel mounted indicators including valve position indicator 110, pressure indicator 111 c, temperature indicator 112 c, bubble indicators 40 c and 70 c, pump speed indicator 115, speed indicator 218, speed indicator 450, discharge pressure indicator 113 c, discharge temperature indicator 114 c and valve position indicator 116.

As hereinbefore set forth, the rotational speed setpoint 109 of the regenerative turbine pump 60 can be calculated by the controller 100 considering various factors. For example, the pump motor speed setpoint 109 must be high enough that the regenerative turbine pump 60, when its impeller (FIG. 2A, 63) is driven at the pump motor speed setpoint 109, will output a minimum pressure equal to or greater than the calculated discharge pressure setpoint 108. Subsequent to reaching the aforementioned minimum rotational speed, the pump motor speed setpoint 109 can be upwardly (or to a limited degree downwardly) adjusted so that the rate of the passage of the regenerative turbine pump 60 impeller's buckets (FIG. 2A, 64) matches the generated bubble production rate. In this way the bubbles flow singularly into the regenerative turbine pump's 60 impeller buckets.

To accomplish this, the controller 100 permits direct interaction between discharge pressure control PLC 102 and pump motor speed control PLC 104 and relays inlet bubble detection apparatus 40 interpolated data that provides the number of bubbles generated per minute (or other time interval) from inlet pressure control PLC 130, via the controller logic PLC 140, to pump motor speed control PLC 104.

Controller logic PLC 140, in addition to and in support of controller logic 101, also stores and distributes to the controller's subsystems PLC 130, 102, 104 upon request parametric data describing the operational performance characteristics and limits of the current configurations of the apparatus subsystems, including information about the installed regenerative turbine pump 60. This pump configuration information can include performance curve data based on the regenerative turbine pump's 60 rotational speed, providing specifications such as maximum discharge pressure, maximum rotational speed, or flow rate, horsepower requirement or NPSHr as a function of the rotational speed. This configuration data is used by the apparatus subsystems' control PLC 130, 102, 104 to verify setpoint data ranges and identify out of limit operational conditions and for operational error control. In addition to this standard pump performance curve information, data regarding the regenerative turbine pump 60 impeller's (FIG. 2A, 63) design is stored accessible to the controller logic PLC 140 and reported to pump motor speed control PLC 104, including the number of impeller buckets (FIG. 2A, 64) along the circumference of the pump's impeller.

Controller logic PLC 140, using the stored subsystem configuration data, controller logic 101, application logic 106, and setpoint data 107, 108, 109, retrieves or calculates and then transmits at operation startup an initial discharge pressure setpoint 108 to the discharge pressure control PLC 102 and an initial pump motor speed setpoint 109 to the pump motor speed control PLC 104. The discharge pressure control PLC 102 then recalculates the discharge pressure setpoint 108 and transmits it, along with the process variable, either the pump discharge pipe 75 pressure sensor 113 signal or the discharge bubble detection apparatus 70 signal, to the discharge pressure control PID 103 so it can position the motorized discharge valve pilot regulator 82. If the bubble collapse rate is insufficient, or the final bubble size is greater than the application specification, or bubbles are to be totally collapsed and yet are still seen by the discharge bubble detection apparatus 70, then the discharge pressure setpoint 108 is increased. The newly calculated higher discharge pressure setpoint 108 is transmitted directly from discharge pressure control PLC 102 to pump motor speed control PLC 104. PLC 104 evaluates the current discharge pressure setpoint 108, and using the stored regenerative turbine pump performance data, in conjunction with the current pump motor speed setpoint 109, determines whether the maximum pressure at the current pump motor speed setpoint 109 is greater than the transmitted newly calculated higher discharge pressure setpoint 108. If the current pump motor speed setpoint 109 is too low, pump motor speed control PLC 104 calculates a new pump motor speed setpoint 109 to cause the regenerative turbine pump 60 to output at least the new discharge pressure setpoint 108 requested by the discharge pressure control PLC 102. Conversely, where the collapsed bubbles are too small or the calculated collapse rate is too great, the discharge pressure setpoint 108, and possibly the pump motor speed setpoint 109 can be lowered. Both of these processes can be implemented using a ranged analog or digital signal representing the speed setpoint, calculated by pump motor speed control PID 105 and transmitted to the variable frequency drive 126, which in turn varies the power frequency supplied to the pump's motor so that it rotates at the pump motor speed setpoint 109. The variable frequency drive 126 continuously returns operational status data, including current actual pump motor rotational speed, to the pump motor speed control PLC 104, which in turn relays this actual pump motor rotational speed data to the pump motor speed control PID 105 as the process variable. Once the final adjustment of the pump motor speed setpoint 109 is complete and bubble collapse occurs as desired, pump motor speed control PLC 104 can switch the process variable used by the pump motor speed control PID 105 from the actual rotational speed signal relayed from the variable frequency drive 126 to the bubble properties signal transmitted from the discharge bubble detection apparatus 70. As with inlet pressure control, the discharge pressure control PID 103 and the pump motor speed control PID 105 process variables can be switched as required between the actual discharge pipe pressure as detected by the discharge pressure sensor 113 or the discharge bubble detection apparatus 70 signal.

Once the minimum discharge pressure setpoint 108 for a bubble collapse rate and final bubble size for a particular application is achieved, fine pump motor speed setpoint 109 adjustment can commence. To accomplish this, pump motor speed control PLC 104 requests the current bubble generation rate from PLC 140, which in turn retrieves the current inlet bubble detection apparatus 40 bubble property values from inlet pressure control PLC 130. Once the current bubble production rate is retrieved, pump motor speed control PLC 104 then calculates the current impeller bucket (FIG. 2A, 64) passage rate as impeller (FIG. 2A, 63) revolutions per minute (or other time interval) multiplied by the total number of impeller buckets on the impeller's circumference, yielding the total number of impeller buckets passing by the pump inlet 61 per minute or other time interval. With this bubble generation rate data and impeller bucket passage rate data, pump motor speed control PLC 104 continuously recalculates a new pump motor speed setpoint 109 that synchronizes the impeller bucket passage rate to the bubble generation rate so that the bubbles are collapsed singly in the impeller buckets 64.

It should be understood that to accomplish the timing between generated bubble and impeller bucket 64, and as a pre-requisite step of application design, the number of bubbles generated and number of impeller buckets should be coordinated so that the impeller can be rotated at the minimum speed to collapse the bubbles as required by an application using a particular impeller design and bubble generation apparatus 30 configuration.

The apparatus can be operated in one of at least three separate purpose modes: as directed by an external device or computer, or as directed by algorithms executed by controller logic PLC 140 using controller 100 and residing controller logic 101, reduction logic 106 and setpoint data 107, 108, 109, or manually using panel mounted controls and indicators. In each of these three modes, the operational parameter values and setpoints, or the algorithms used to calculate them, as well as the useful subsystem process variable identities, are known and are input as controller application logic 106 and setpoint data 107, 108, 109 intended and expected to achieve a particular operational result.

In another mode, where the controller 100 is used as a tool to determine the optimal operational parameter values and the identities of those process variables required to produce a particular functional result. In this experimental or application development operational mode, the setpoint data 107, 108, 109 submitted represent test value ranges, or are algorithms used to calculate test value ranges, and include target performance specifications for bubble production and collapse. In this mode, the application logic 106 can provide both an operational test sequence algorithm that controls how each setpoint should be varied across the submitted setpoint data 107, 108, 109 range, as well as an algorithm and criteria to evaluate each set of operational parameter values against the target application performance specifications. During test execution, application logic 106 stores those operational setpoints that provide useful results, either a good fit or a poor match to the target performance.

The controller allows automatic sequential execution of operational trials using electronically stored inlet and discharge pressure setpoint values or value ranges and pump speed setpoint values or value ranges that may produce desirable performance characteristics, as required by a particular application. The controller 100 automatically recalculates and varies the operational setpoints using the originally input setpoint values or value ranges and value modification algorithms residing in the controller. Alternately, the operational trials could be directed using an external computer, PLC or other functionally equivalent device to submit test setpoint data 107, 108, 109 and test application logic to controller PLC 140, through external interface PLC 118. Once testing is complete, result data can be read by or uploaded to an external computer or device for storage or further analysis. Rather than storing only criteria matching operational test data, all result data could be stored, locally in the controller 100 or on a remote computer or storage device for further analysis. In this way, an application protocol describing the operational conditions and process variable selections most likely to produce a desired result with the apparatus can be developed using the apparatus and controller 100 as reporting those setpoint combinations yielding desirable or best fit operational characteristics using controller residing result evaluation algorithms.

The controller can be used as an analytical tool to determine the optimal operational parameter values required for producing bubbles of a certain size and collapsing them at a specific rate to plasma hot spots or as required by a particular application. The controller allows automatic sequential execution of operational trials using electronically stored inlet and discharge pressure setpoint values or value ranges and pump speed setpoint values or value ranges that may produce desirable performance characteristics, as required by a particular application. The controller automatically recalculates and varies the operational setpoints using the originally input setpoint values or value ranges and value modification algorithms residing in the controller. The controller concurrently records and subsequently analyses the trial operational results. In this way, an application protocol describing the operational conditions and process variable selections most likely to produce a desired result with the apparatus can be developed using the apparatus and controller as reporting those setpoint combinations yielding desirable or best fit operational characteristics using controller residing result evaluation algorithms.

Copending U.S. patent application Ser. No. ______, titled “Chemical Reactor System and Method using Regenerative Turbine Pump to Produce Fuel Gas,” discloses a particular application and is filed contemporaneously herewith. The disclosure of this application is expressly incorporated herein by reference.

FIG. 6 is a flowchart showing processing steps that are carried out by the controller logic 101 of the present invention. Beginning in step 1010, the controller logic 101 inventories subsystems and obtains the status of the subsystems. A determination is made in step 1020 as to whether any errors are present. If errors are present, in step 1030 the errors are displayed and the status of the errors is transmitted for review, and then the system is halted in step 1040. Otherwise, if there are no errors in step 1020, a determination is made as whether to initiate automatic control mode in step 1050. If a negative determination is made, in step 1060 another determination is made as to whether to initiate manual control mode. If a negative determination is made, yet another determination is made as to whether to initiate external control mode in step 1070. If external control mode is not executed, a control mode error is transmitted (“thrown”) in step 1080 and the processing reverts to step 1030 in which error stats are displayed and the status is transmitted.

If automatic control mode is initiated in step 1050, the setpoint data 107, 108, 109 is obtained from controller in step 1090, and step 1120 occurs. If manual control mode is initiated in step 1060, the setpoint data 107, 108, 109 are obtained from an operator panel in step 1100, and step 1120 occurs. If external control mode is initiated in step 1070, the setpoint data 107, 108, 109 are obtained from an external device in step 1110, and step 1120 occurs. In step 1120, the setpoint data is transmitted, the pump 60 and subsystems are started and the status is obtained. Thereafter, in step 1130 a determination is made as to whether the setpoint range is acceptable. If a negative determination is made, an input setpoint range error is thrown in step 1140, and the processing reverts to step 1030. If the setpoint range is acceptable, reduction logic 106 is performed in step 1150.

Next, in step 1160, a determination is made as to whether a subsystem error exists. If a positive determination is made, the processing reverts to step 1030. If no errors exist, a determination is made as to whether to initiate operational command in step 1170. If a positive determination is made, external or manual control mode operation command is processed in step 1180, and then, in step 1190, a determination is made as to whether to initiate new setpoint data. If a positive determination is made, the processing reverts to step 1050. If not, the processing reverts to step 1150.

If operational command is not initiated in step 1170, a determination is made as to whether there is a change in operational mode in step 1200. If a positive determination is made in step 1200, a determination is then made as to whether to halt the request in step 1210. If a positive determination is made, the processing reverts to step 1030. Otherwise, the processing reverts to step 1050. If operational mode change is not performed in step 1200, a determination is made as to whether to request subsystem data in step 1220. If a positive determination is made, the subsystem data request is processed in step 1230, and the operation of the system continues in step 1240, and the processing reverts to step 1150. Otherwise, the operation of the system continues in step 1240, and the processing reverts to step 1150.

FIG. 7 is a flowchart showing processing steps of the reduction logic 106. Beginning in step 1300, bubble generation logic is performed. In step 1310, a determination is made as to whether any error states or events are present. If any error states or events are present, the processing reverts to step 1150. Otherwise, bubble collapse logic is performed in step 1320. In step 1330, a determination is made as to whether any error states or events are present. If any error states or events are present, the processing reverts to step 1150. If step 1330 determines that there are no error states or events, control returns to step 1300.

FIG. 8 is a flowchart showing processing steps of the bubble generation logic. Beginning in step 1400, a determination is made as to whether any setpoints are out of range. If a positive determination is made, a bubble generation setpoint error is thrown in step 1410 and the processing reverts to step 1300. Otherwise, a determination is made as to whether the bubble generation is acceptable in step 1420. If a positive determination is made, the processing reverts to step 1300. If the bubble generation is not acceptable, the inlet pressure setpoint is adjusted to correct bubble generation in step 1430, and the process reverts to step 1400.

FIG. 9 is a flowchart showing processing steps of the bubble collapse logic. Beginning in step 1500, a determination is made as to whether any setpoints are out of range. If a positive determination is made, a bubble collapse setpoint error is thrown in step 1510 and the processing reverts to step 1320. Otherwise, a determination is made as to whether the bubble collapse is acceptable in step 1520. If a positive determination is made, the processing reverts to step 1320. If the bubble collapse is not acceptable, the discharge pressure setpoint is adjusted to correct bubble collapse in step 1530. Next, in step 1540, a determination is made as to whether the available pressure is too low. If a negative determination, the process reverts to step 1500. Otherwise, the pump speed setpoint is increased in step 1550, and the process reverts to step 1500.

It will be understood that the embodiments described herein are merely exemplary and that a person skilled in the art may make many variations and modifications without departing from the spirit and scope of the invention. All such variations and modifications are intended to be included within the scope of the invention as defined by the appended claims. 

What is claimed is:
 1. A system for the formation and collapse of bubbles, the system comprising: a bubble generator for generating bubbles in a fluid; a regenerative turbine pump for receiving the fluid and the bubbles; at least one sensor sensing at least one process parameter associated with operation of the regenerative turbine pump; and a controller in communication with the at least one sensor, the controller receiving the at least one process parameter, processing the at least one process parameter, and adjusting operation of the regenerative turbine pump based upon processing of the at least one process parameter.
 2. The system of claim 1, wherein the regenerative turbine pump includes an impeller blade defining a plurality of buckets.
 3. The system of claim 2, wherein the buckets are sized to receive and move a singular bubble.
 4. The system of claim 3, wherein the process parameter comprises at least one of the rotational speed of the buckets, discharge pressure, and temperature.
 5. The system of claim 4, further comprising a bubble detection apparatus attached to the pump, the bubble detection apparatus sized to detect the number and size of the bubbles.
 6. The system of claim 5, wherein the bubble generator comprises a venturi.
 7. The system of claim 5, wherein the bubble generator comprises an eductor.
 8. The system of claim 5, wherein the bubble generator comprises an injector for injecting the bubbles into the fluid.
 9. The system of claim 4, wherein the controller transmits a speed setpoint signal to the pump and the controller calculates the speed, pressure, or flow rate of the pump.
 10. The system of claim 9, wherein the system operates in a closed loop configuration.
 11. The system of claim 10, wherein the at least one sensor senses at least one process parameter associated with operation of the bubble generator.
 12. The system of claim 11, wherein the controller is in communication with the at least one sensor, the controller receiving the at least one process parameter, processing the at least one process parameter, and adjusting operation of the bubble generator based upon processing of the at least one process parameter.
 13. A method for the formation and collapse of bubbles, the method comprising the steps of: producing a stream of bubbles from a liquid; delivering the stream of bubbles to a regenerative turbine pump having an impeller defining a plurality of buckets; collapsing the bubbles; and monitoring a process parameter associated with the bubbles using a controller and at least one sensor; and adjusting operation of the regenerative turbine pump based upon monitoring of the parameter.
 14. The method of claim 13, wherein the bubbles are collapsed in individual bucket chambers of the regenerative turbine pump.
 15. The method of claim 14, wherein the bubbles are entrained in a helical flow in the chambers of the pump.
 16. The method of claim 15, further comprising the step of monitoring pressure or flow rate of the stream of bubbles using at least one sensor and the controller in communication with the at least one sensor.
 17. The method of claim 16, further comprising the step of determining whether the pressure or the flow rate is within an acceptable range using the controller.
 18. The method of claim 17, further comprising the step of adjusting operation of the regenerative turbine pump in response to monitoring of the pressure or the flow rate.
 19. A system for the formation and collapse of bubbles, the system comprising: a bubble generator for generating bubbles in a fluid; a regenerative turbine pump for receiving the fluid and the bubbles; at least one sensor sensing at least one process parameter associated with operation of the bubble generator; and a controller in communication with the at least one sensor, the controller receiving the at least one process parameter, processing the at least one process parameter, and adjusting operation of the bubble generator based upon processing of the at least one process parameter.
 20. The system of claim 19, wherein the regenerative turbine pump includes an impeller blade defining a plurality of buckets.
 21. The system of claim 20, wherein the buckets are sized to receive and move a singular bubble.
 22. The system of claim 21, wherein the bubble generator comprises a venturi.
 23. The system of claim 21, wherein the bubble generator comprises an eductor.
 24. The system of claim 21, wherein the bubble generator comprises an injector for injecting the bubbles into the fluid. 